Photographs of the webs of approximately 113 species in 52 genera show that the web architecture of linyphioid spiders (Linyphiidae and Pimoidae) present many variations on a single basic pattern. Nearly all species built webs with a more or less horizontal, continuous sheet with an open space just below the sheet. However, the details in the designs showed great diversity; we recognized >50 web traits, including positions relative to the ground or large objects; sheet shapes and orientations; secondary sheets; “slime” on the sheet; patterns and densities of lines in sheets; visible droplets on sticky lines; upward and downward directed dimples in the sheet with tensor lines; primary and secondary frame lines; retreats; and the presence, location, and designs of associated tangles. This survey probably substantially underestimates both intraspecific and intrageneric diversity of web forms. Intrageneric comparisons in just over 20 genera documented varying degrees of intrageneric variation; some genera show striking differences. Several web designs were widely distributed: sheets with dense tangles above commonly had arrays of lines attached to the sheet's upper surface; downward dimples in sheets commonly occurred at sites where the sheet curved upward, but upward-directed dimples were rare and small; and sheets built next to the surface of the ground almost always lacked extensive tangles above them. New web patterns not previously reported for linyphiid webs include: sandwich webs (pairs of closely spaced, otherwise naked sheets); extensive vertical sheets next to tree trunks; tubular retreats at the edges of the sheet where the spider rests; trough-like sheets just above the upper surface of a curled leaf; sizeable, apparently sticky droplets densely covering many lines that were apparently placed in pairs in the sheet; long sheet lines that converge at one corner; runways to a sheltered site where the spider waits beyond the sheet's edge; and apparent skeleton lines in the sheet (probably from early stages of construction). Patterns of lines within the sheet may reflect patterns of movement during sheet construction behavior. We propose that some webs on the substrate function to extend the spider's sensory field rather than detain prey and that some tangles below and perhaps some above the sheet may function to defend the spider from enemies. A suite of linyphiid traits, including leg, chelicera, and spinneret morphology; details of web design, such as numerous small upward-directed dimples in dome-shaped sheets but fewer, large downward-directed dimples in cup-shaped sheets; and attack behavior, appears to function to increase the speed with which spiders attack prey. The functions of many architectural features remain obscure.

We describe the only known tetraploid parthenogenetic species of amniote that has haploid genomes from four distinct ancestral bisexual (gonochoristic) species. These genomes were brought together through three hybridization events that occurred over a time span of hundreds or thousands of years, the last of which occurred recently in captivity without any experimental manipulation.

A joint expedition between the Museum of Comparative Zoology of Harvard University (Cambridge, Massachusetts, USA) and the Museo Argentino de Ciencias Naturales (Buenos Aires, Argentina) explored outcrops in west-central Argentina during autumn of 1958. The team led by Alfred S. Romer collected fossils from several Cenozoic outcrops from Mendoza, San Juan, and La Rioja provinces. Some of the recovered fossils were previously published, including gastropods, birds, turtles, and mammals. However, other specimens, which belong to the Vertebrate Paleontology collection at the Museum of Comparative Zoology, remained unknown and even uncatalogued until the present contribution. Here, we present this peculiar collection for the first time, providing an updated taxonomic list of the vertebrate remains. Based on the studied material, we identified 1) Glyptodontidae (cf. Propalaehoplophorus), Dasypodidae (Stenotatus sp.), Mesotheriidae (cf. Altitypotherium), Macraucheniidae (Cramaucheniinae gen. et sp. indet.) and Rodentia indet. in the Aisol Fm.; 2) Megatheriidae (Pyramiodontotherium sp.) and Macraucheniidae (Macraucheniinae gen. et sp. indet.) in the Tunuyán Fm.; 3) Dasypodidae indet. in the Mariño Fm.; 4) Hegetotheriidae (Hemihegetotherium sp., Pachyrukhinae gen sp. indet., Paedotherium sp.) and Rodentia indet. in the Pilona Fm.; and 5) Cingulata indet., Mesotheriidae (Pseudotypotherium sp.), Hegetotheriidae (Tremacyllus sp.), Chinchiliidae indet., and Hydrochoeridae indet. in the Huachipampa Fm. The reports of the Romer collection from Argentina allow the establishment of biochronological correlations between the lesser-known faunas from west-central Argentina and faunas from other areas of South America.

Despite being among the largest and most conspicuous geckos across southern and eastern Africa, the toe-padded species of Chondrodactylus have remained one of the most taxonomically difficult groups of African lizards, due chiefly to their overall morphological conservativeness accompanied by high intraspecific variation. Current recognition of taxa is based on recent molecular phylogenetic analyses, but the application of the currently recognized nomina to particular populations has not yet been presented. We present a much-expanded multigene analysis of 234 representatives of the genus Chondrodactylus that supports the recognition of 6 species-level taxa, one without toepads, C. angulifer, as sister to five with pads: C. bibronii, C. turneri, C. laevigatus, C. pulitzerae, and C. fitzsimonsi. In general, the species can be recognized on the basis of the relative size of chin and gular scales, dorsal scalation, and head shape. However, the most widespread species, C. laevigatus is only very subtly distinct from C. turneri, with which it is likely parapatric in East Africa (although western populations of C. laevigatus are unambiguously diagnosable from all other congeners). Intraspecific divergences are high in some of the species. In C. fitzsimonsi there is evidence of shared nuclear haplotypes with C. pulitzerae and potential morphological evidence for hybridization or introgression with C. laevigatus. Chondrodactylus turneri exhibits a mitochondrial gene rearrangement that is unique among all geckos followed by an insertion of roughly 200 base pairs that do not correspond to known sequences. Most Chondrodactylus species are primarily distributed in arid to semiarid southwestern Africa, where as many as 4 species occur in sympatry in northern Namibia. In contrast, C. turneri is limited to the lowlands of the southeast and C. laevigatus follows the “arid-corridor” traversing sub-Saharan Africa southwest to northeast.

John James Audubon, the self-trained artist and naturalist, is best known for The Birds of America. Although his life has been widely studied in biographies, his birth mother and the confusing series of names assigned to him during the early decades of his life have never been satisfactorily explained, leading to many misconceptions and controversies. New documentary evidence, including an important unpublished letter, allows us in the first part of this article to connect the historical dots to firmly establish his ancestry and to counter misunderstandings about it. The documents analyzed in the second part clear up the mysteries surrounding his early identities and pseudonyms, which prove to have been both intentional and strategic, and also underline that Jeanne Rabine was his mother. In the process, the study will also illuminate elements in the large cache of Audubon's early ornithological pastels and the manuscript of his earliest autobiography held by the Ernst Mayr Library and Archives of the Museum of Comparative Zoology and Houghton Library of Harvard University.

Squamates (lizards, snakes, and their kin such as amphisbaenians, or “worm lizards”) represent the world's most diverse clade of terrestrial vertebrates with ∼11,000 described extant species, representing key components in many of the world's most diverse ecosystems. With an evolutionary history dating back at least to the Middle Triassic at 242 Ma, the squamate Tree of Life also features numerous diverse but extinct branches, with hundreds of fossil species found all over the world. Despite their biological relevance both today and in the geological past, there remains a centuries-old controversy on how the major lineages of squamates are related to each other, with a direct impact on studies in ecology, evolution, paleontology, toxinology, and other fields. Here, we provide a historical overview of this long research tradition, from 19th century naturalists to 21st century phylogenomics, with special emphasis on several recent advances over the last two decades. These insights have had a dramatic effect on our understanding of the squamate Tree of Life and clarify several possible future research agendas. We provide an integrative perspective derived from genomics, morphology, and the fossil record and propose several points of synthesis in our current knowledge of broadscale squamate evolution and systematics. Key topics of interest include dating the origin and early evolution of lizards, the phylogenetic origin of snakes, the evolution of venom, recent agreements between morphological and molecular squamate evolutionary trees, genomic patterns of evolution, and the integration of morphological and molecular data sets. We conclude by providing perspectives on possible advancements in the field, directing researchers to promising future lines of investigation that are necessary to further expand our synthetic knowledge of squamate evolution.

Andrew Garrett, a self-taught naturalist and artist best known for his work as a conchologist and ichthyologist, spent his entire adult life documenting the flora and fauna of the Pacific Islands. Although he focused primarily on molluscs and fishes, he collected and described many other organisms, both marine and terrestrial. He also made hundreds of watercolor drawings, primarily of fishes but also molluscs and other marine invertebrates, most of which have never been published. Although he produced a number of publications on his own, his greatest legacy lies in documenting the rich faunas of these islands, which have since suffered high rates of extinction, and in making vast amounts of zoological specimens available to others who later published on his material, describing countless numbers of new species.